Rear release contact retention assembly

ABSTRACT

An electrical connector assembly that includes means for demountably retaining electrical contacts within the connector. The contact retention assembly includes a rearwardly extending tubular contact retention tower that is resiliently and radially expandable so that contacts may be demountably retained within the passage that extends through the contact retention tower. The rearwardly extending contact retention tower is cylindrically shaped with an axial passage therethrough containing a forwardly facing shoulder to provide a rearward stop when an electrical contact is mounted therein. Another insert, having a hole therein, may be mounted around the tubular contact retention tower to prevent radial expansion thereof while the insert is in place.

United States Patent [191 Eifler et al.

[451 May21, 1974 REAR RELEASE CONTACT RETENTION ASSEMBLY [75] Inventors:Raymond J. Eifler, Farming'ton,

Mich.; Walter F. Hennessey, Sidney,

[21] Appl. N0.: 318,341

[56] References Cited UNITED STATES PATENTS 3,101,229 8/1963 Yopp 339/59M 3,727,172 4/1973 Clark 3,500,297 3/1970 Bac' 339/217 R 3,638,165l/l972 Anhalt et al. 339/59 R 3,165,369 l/1965 Maston 339/59 3,068,44312/1962 Nava et a1. 339/217 S Primary Examiner-Joseph H. McGlynnAssistant Examiner-Robert A. Hafer Attorney, Agent, or Firm-Raymond J.Eifler 5 7] ABSTRACT An electrical connector assembly that includesmeans for demountably retaining electrical contacts within theconnector. The contact retention assembly includes a rearwardlyextending tubular contact retention tower that is resiliently andradially expandable so that contacts may be demountably retained withinthe passage that extends through the contact retention tower. Therearwardly extending contact retention tower is cylindrically shapedwith an axial passage therethrough containing a forwardly facingshoulder to provide a rearward stop when an electrical contact ismounted therein. Another insert, having a hole therein, may be mountedaround the tubular contact retention tower to prevent radial expansionthereof while the insert is in place.

5 Claims, 4 Drawing Figures REAR RELEASE CONTACT RETENTION ASSEMBLYBACKGROUND OF THE INVENTION This invention relates to electricalconnectors of the type having a plurality of contacts in one connectormember which are mateable with a plurality of contacts in anotherconnector member when the members are interengaged. This invention ismore particularly related to a retention mechanism in the connectormembers which permit the contacts to be snapped into their operativeposition in respective bores in the insulators of the connector membersand also permits the contacts to be released for withdrawal from therespective bores by use of a suitable release tool.

Various systems have been employed in the electrical connector art forsnap-in retention of the contacts in the insulation bodies of theconnector members. Most systems of this general type utilize individualforward extending retention clips which circumscribe the respectivecontact members and are either mounted on the contacts for engagementagainst respective shoulders in the insulator bores or mounted in thebores for engagement against respective shoulders on the contacts. Oneexample of this type of contact retention mechanism may be found in US.Pat. No. 3,158,424 entitled Contact Mounting issued Nov. 24, l964 to R.Bowen.

ln electrical connector assemblies where it is not necessary to haveindividual contact retention mecha nisms, the individual contactretention mechanisms may be assembled into a single assembly whichdemountably retains a plurality of electrical contacts, each of which isindependently released. One example of a single assembly of demountablyretained electrical contacts may be found in US Pat. No. 3,l65,369entitled Retention System for Electrical Contacts issued Jan. 12, 1965to J. W. Maston.

Accordingly, the inventor of this invention set out to invent a contactretention mechanism that accomplished the results of the Maston andBowen patents but by entirely different structures and arrangements.

SUMMARY OF THE INVENTION This invention provides an alternate approachto retaining the electrical contacts within a connector assemblyheretobefore undisclosed. The invention, which is a novel contactretention assembly, provides a means for demountably assembling anelectrical contact within a connector assembly which does not requirethe disassembly of the connector to remove the contacts. Further, itdoes not require removal of all contacts to replace or remove any one ofthe contacts.

The invention is an electrical connector assembly characterized by acontact retaining member that includes a plurality of tubular contactretention towers integral with said retention member (20). Each of thetubular contact retention towers (25) extend rearwardly from theretention member (20) and have on the inside thereof a forward facingshoulder (27) for preventing the rearward movement of a contact mountedin the retention tower (25). Each of the tubular retention towers 25 arefurther characterized by the fact that they are resiliently and radiallyexpandable to allow the enlarged section (41) of a contact (40) to passtherethrough upon forward insertion of the contact into the axialpassage in the tower (25).

In one embodiment of the invention the electrical connector unitcomprises: a forward member l0) having a forward face (16), a rearwardface and a bore (18) extending therethrough from said forward face (16)to said rearward face, the bore (18) having an enlarged rearward sectionopening at said rearward face, a smaller forward section and a rearwardfacing shoulder (13); a wafer (20), mounted against the rearward face ofthe insulator member (10), having a passage therethrough axially alignedwith said insulator bore (18), the insulator bore (18) and said waferpassage adapted to receive an electrical contact member (40) which isinsertable in said bore (18) and passage from the rear, the electricalcontact (40) of the type having an enlarged section that includes arearwardly facing shoulder (43) and a forwardly facing shoulder (46)thereon with said forwardly facing shoulder (46) engageable with saidinsulator rearwardly facing shoulder (13) to limit forward movement ofthe contact member; and a tubular contact retention tower (25) integralwith said wafer and coaxial with said wafer passage, said tubularcontact retention tower (25) extending rearwardly from said wafer to afree-end, said tubular contact retention tower (25) having a centralpassage therein that includes a forwardly facing shoulder (27 saidtubular contact retention tower being resiliently and radiallyexpandable to permit said enlarged contact section (41) to passtherethrough upon forward insertion of the contact member (40) into thepassage and bore (18), said tubular contact retention tower contractingbehind the rearwardly facing shoulder (43) on the contact member (40) sothat the forwardly facing shoulder (27) engages the rearwardly facingshoulder (43) on the contact member to limit rearward movement thereofin the passage and bore. Said tubular contact retention tower beingsubstantially rigid in the axial direction when in its contractedposition so as to provide a positive stop against rearward movement ofthe respective contact member. To prevent the radial expansion of thetubular contact retention towers (25) or to increase the force necessaryto expand the retention tower (25), a second insert (30) having a towerreceiving passage may be removably mounted against the wafer (20). Asdescribed herein, the electrical contact retention member (20) issandwiched between a forward insert (10) and a'rear insert (30).

Accordingly, it is an object of this invention to provide an alternateapproach to prior art contact mounting systems.

It is also an object of this invention to provide a structure thatincludes a plurality of contact retention towers for retaining contactswithin an electrical connector.

It is still another object of this invention to provide a contactmounting mechanism for an electrical connector in which the contactmember may be inserted in the bore of an insulation block from the rearface thereof, caused to be locked in the bore against axial movement ineither direction, and which is removable by manipulation entirelyrearwardly of the insulation block, access to the front of the block orthe front of the contact terminal being wholly unnecessary.

It is a further object of this invention to provide a snap-in contactretention memberfor an electrical connector comprised of a unitary bodyhaving a plurality of resiliently and radially deformable contactretention towers formed therein that releasably retain a plurality ofcontacts in respective towers in a manner that allows the removal of oneelectrical contact without the removal of all electrical contacts.

The above and other objects and features of the in vention will becomeapparent from the following de-- tailed description taken in conjunctionwith the accompanying drawings and claims that form a part of thisspecification.

BRIEF DESCRIPTION OF .THE DRAWINGS FIG. I is a partial cross-sectionalview of an electrical connector assembly that includes an electricalcontact retaining mechanism that embodies the principles of thisinvention.

FIG. 2 is a partial cross-sectional view taken along lines II'II of FIG.1.

FIG. 3 is a partial cross-sectional viewof the electrical connectorassembly shown in FIG. 1, with an electrical contact located in apartially inserted position before the contact retention towers havecontracted behind the contact shoulder.

FIG. 4 is an alternate embodiment of the assembly electrical connectorshown in FIG. 1 wherein the rear insert is a removably mounted rigidmaterial that prevents the radial deflection of the retention towers.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings, FIG.1 illustrates a novel contact retention insert (20) sandwiched between aforward insert and a rear insert (30). Forward insert (10) includes aforward face (16), a rearward facing shoulder (13) and a passage (18)extending from the rear face to the front face. Passage'US) in theforward insert (10) is sized to receive: the forward portion ofelectrical contact (40) and to provide a positive stop (13) againstfurther forward movement of the contact (40) and to provide a positivestop (13) against further forward movement of the contact (40) once itis inserted in the passage 18). The rear insert (30), which in thisembodiment is comprised of a resiliently deformable material such asrubber, has a rearface (33) and a passage aligned with passage (18) inthe forward insert (10). The passage in the rear insert (30) is sized toreceive rearwardly extending retention towers (25) which are an integralpart of the retention insert (20). The retention insert (20) has aforward face (26), a rearward face (23) and one or more retention towers(25) extending from the rearward face of the retention insert (20). Eachof the retention towers (25) includes an internal forwardly facingshoulder (27) that engages the rearwardly facing shoulder (43) of thecontact (40) to prevent the rearward movement of the contact (40) onceit is inserted into the passage (18). It is the function of the rearinsert (30) to provide a fluid-tight seal around the contacts andbetween adjacent contact retention towers (25). Attached to electricalcontact (40) is an incoming lead (50). It is the function of the forwardinsert 10), which is generally comprised of plastic, to provide theforward stop means (13) and prevent radial movement of the contact (40)once it is inserted in the passage(l8).

FIG. 2 is a partial cross-sectional view of the embodiment shown in FIG.1 taken along lines lI-,- II. This view illustrates how the electricalcontact (40) is seated in the retention tower (25). This view alsoillustrates that the plastic retention towers (25.) are radiallydeflectable because of the splits which extend the length of the tower(25) allowing the sides of the tower to be deflected radially. In thisembodiment since the rear insert (30) is made ofa resilient materialsuch rubber,

release and removal of the contact terminal.(40) may be simplyaccomplished by merely inserting a suitable tool from the rear so as todeflect the contact retaining shoulders of the retention tower (25)beyond the shoulder (43) of the contact (40), thus clearing a path forrearward withdrawal of the contact (40) out of the bore. One type oftool which is useful for this purpose is a tubular plastic tool whichmay be slideably engaged over the wire and then over the rear portion ofthe contact (40).

FIG. 3 illustrates the connector assembly portion shown in FIG. 1wherein the contact (40) is located in a partially inserted positionbefore the contact retention shoulders (27) have contracted into placebehind the rearward facing shoulder (43) of the contact (40) to preventrearward movement of the contact (40). This figure illustrates how therearward facing shoulder (13) of the forward insert (10) prevents thecontact from moving forward once the forward facing shoulder (46) of thecontact (40) engages such rearward facing shoulder (13). The drawingfurther illustrates how the enlarged portion (41) of the contact (40)radially deflects the contact retention tower (25) before moving intoits locked position by the contracting of the forwardly facing shoulder(27) behind the rearwardly facing shoulder (43) of the contact (40).Since the forward insert'(10) is made of a fairly rigid material e.g.plastic and the passage 18) is fairlylong withrespect to the contact(40) body, movement of the contact (40) in a radial direction isprevented by the action of the walls of the passage (18) against thecontact (40).

FIG. 4 illustrates a partial cross-sectional view of an electricalconnector assembly that embodies alternate features of this -invention.In this embodiment, the electrical connector assembly includes agenerally tubular metal shell (16) which has mounted therein a forwardinsert (10), a contact retaining insert (20), a removable locking insert(30), and a removable rubber insert (70) for sealing out moisture. Inthis embodiment the locking insert (30) is comprised'of a rigid materialsuch as plastic which, when mounted into position against the retaininginsert (20) and around the contact retaining towers (25), prevents thetowers from being radially expanded and the contact (40) from beingremoved. In this embodiment the inserts (30, 70) are removably mountedwithin the tubular shell and it is necessary to first remove the insertsbefore removing one or more of the contacts (40) retained by the contactretaining insert (20) and the forward insert (10). In this embodimenttherearward facing shoulder (13) of the forward insert that preventsfurther movement of the contact (40) when seated is located within theforward insert instead of extending from the rear as shown in FIGS. 2and 3.

While a preferred embodiment of the invention has been disclosed, itwill become apparent to those skilled in the art that changes may bemade to the invention as set forth in the appended claims, and, in somecases, certain features of the invention may be used to advantagewithout corresponding use of other features. Accordingly, it is intendedthat the illustrative and descriptivc materials herein be used toillustrate the principles of the invention and not to limit the scopthereof.

Having described the invention, what is claimed is:

1 An electrical connector unit comprising:

a body of insulating material having a plurality of passagestherethrough from a front face to a rear face, each of said passagesadapted to receive respective electrical contacts therein which areinsertable from the rear, each of said electrical contacts having anenlarged section defining a rearwardly facing shoulder and a forwardlyfacing shoulder; and

a plurality of tubular contact retention towers integral with saidinsulation body and coaxial with respective passages, each tubularretention tower extending rearwardly from the rear face of saidinsulating body to a rearward free end, each tubular tower having on theinside thereof a forward facing shoulder, the opposite side of saidshoulder being tapered radially inwardly from the inside wall of saidtubular tower, so that said forwardly facing shoulder and said oppositetapered side forma projection inside said tower that spaces the insidewall of said tower, at said rearward free end, from an electricalcontact when an electrical contact is inserted into said tower, each ofsaid tubular towers being resiliently and radially expandable to permitthe enlarged section of a respective contact member to pass therethroughupon forward insertion of the contact member into a respective passage,the forward facing shoulder of said tubular tower contracting behind therearwardly facing shoulder on the contact member to provide a positivestop against rearward movement of the respective contact member.

2. The combination as recited in claim 1 including means for preventingsaid contact retention towers from being expanded in a radial direction,said means being removably mounted against the rear face of said body.

3. The combination as recited in claim 2 wherein said means forpreventing said towers from expanding in a radial direction comprises aninsert having a forward face and a rearward face, removably mounted withits forward face against the rearward face of said body, said insertcomprised of a rigid material having a plurality of holes therethroughaxially aligned with the passages of said body, said holes in saidinsert sized to receive said rearwardly extending retention towers in amanner that permits the walls defining said holes to contact saidretention towers and thereby prevent radial expansion of said latchingtowers.

4. The combination as recited in claim 1 including an insert having aforward face and a rearward face mounted with its forward face againstthe rearward face of said body, said insert comprised of a resilientlydeformable material having a plurality of holes therethrough, from saidfront face to said rear face, axially aligned with the passages of saidbody, said holes in said insert sized to receive said rearwardlyextendingretention towers in a manner that permits the walls definingsaid holes to contact said retention towers and the rear portion of saidcontact, said insert forming a fluid tight seal around each of saidcontacts and increasing the restoring force of said resilientlyexpandable retention towers and the force required to radially expandsaid retention towers.

5. An electrical connector unit comprising:

a forward insulator member having a forward face, a rearward face, and abore extending therethrough from said forward face to said rearwardface, said bore having an enlarged rearward section opening at saidrearward face and a conduit axially aligned with said bore and extendingfrom said rear face;

wafer having a rearward face and a forward face, said forward facemounted against the rearward face of the insulator member, said waferhaving a passage therethrough axially aligned with said insulator boreand which receives said insulator conduit, said insulator bore andconduit and said wafer passage adapted to receive an electrical contactmember which is insertable in said bore, conduit, and passage from therear of said wafer, the electrical contact of the type having anenlarged section that includes a rearwardly facing shoulder and aforwardly facing shoulder thereon, said forwardly facing shoulderengageable with the free end of said conduit of said insulator to limitforward movement of the contact member; and

tubular contact retention tower integral with said wafer and axiallyaligned with said wafer passage, said tubular contact retention towerextending rearwardly from the rearward face of said wafer to a rear freeend, said tubular contact retention tower having a central passagetherein that includes a forwardly facing shoulder, said tubular contactretention tower being resiliently and radially expandable to permit saidenlarged contact section to pass therethrough upon forward insertion ofthe contact member into the passage and bore, said tubular contactretention tower contracting behind the rearwardly facing shoulder on thecontact member so that the forwardly facing shoulder within the tubularcontact retention tower engages the rearwardly facing shoulder on thecontact member to limit rearward movement thereof in the passage andbore, said tubular contact retention tower being substantially rigid inthe axial direction when in its contracted position so as to provide apositive stop against rearward movement of the respective contactmember.

1. An electrical connector unit comprising: a body of insulatingmaterial having a plurality of passages therethrough from a front faceto a rear face, each of said passages adapted to receive respectiveelectrical contacts therein which are insertable from the rear, each ofsaid electrical contacts having an enlarged section defining arearwardly facing shoulder and a forwardly facing shoulder; and aplurality of tubular contact retention towers integral with saidinsulation body and coaxial with respective passages, each tubularretention tower extending rearwardly from the rear face of saidinsulating body to a rearward free end, each tubular tower having on theinside thereof a forward facing shoulder, the opposite side of saidshOulder being tapered radially inwardly from the inside wall of saidtubular tower, so that said forwardly facing shoulder and said oppositetapered side form a projection inside said tower that spaces the insidewall of said tower, at said rearward free end, from an electricalcontact when an electrical contact is inserted into said tower, each ofsaid tubular towers being resiliently and radially expandable to permitthe enlarged section of a respective contact member to pass therethroughupon forward insertion of the contact member into a respective passage,the forward facing shoulder of said tubular tower contracting behind therearwardly facing shoulder on the contact member to provide a positivestop against rearward movement of the respective contact member.
 2. Thecombination as recited in claim 1 including means for preventing saidcontact retention towers from being expanded in a radial direction, saidmeans being removably mounted against the rear face of said body.
 3. Thecombination as recited in claim 2 wherein said means for preventing saidtowers from expanding in a radial direction comprises an insert having aforward face and a rearward face, removably mounted with its forwardface against the rearward face of said body, said insert comprised of arigid material having a plurality of holes therethrough axially alignedwith the passages of said body, said holes in said insert sized toreceive said rearwardly extending retention towers in a manner thatpermits the walls defining said holes to contact said retention towersand thereby prevent radial expansion of said latching towers.
 4. Thecombination as recited in claim 1 including an insert having a forwardface and a rearward face mounted with its forward face against therearward face of said body, said insert comprised of a resilientlydeformable material having a plurality of holes therethrough, from saidfront face to said rear face, axially aligned with the passages of saidbody, said holes in said insert sized to receive said rearwardlyextending retention towers in a manner that permits the walls definingsaid holes to contact said retention towers and the rear portion of saidcontact, said insert forming a fluid tight seal around each of saidcontacts and increasing the restoring force of said resilientlyexpandable retention towers and the force required to radially expandsaid retention towers.
 5. An electrical connector unit comprising: aforward insulator member having a forward face, a rearward face, and abore extending therethrough from said forward face to said rearwardface, said bore having an enlarged rearward section opening at saidrearward face and a conduit axially aligned with said bore and extendingfrom said rear face; a wafer having a rearward face and a forward face,said forward face mounted against the rearward face of the insulatormember, said wafer having a passage therethrough axially aligned withsaid insulator bore and which receives said insulator conduit, saidinsulator bore and conduit and said wafer passage adapted to receive anelectrical contact member which is insertable in said bore, conduit, andpassage from the rear of said wafer, the electrical contact of the typehaving an enlarged section that includes a rearwardly facing shoulderand a forwardly facing shoulder thereon, said forwardly facing shoulderengageable with the free end of said conduit of said insulator to limitforward movement of the contact member; and a tubular contact retentiontower integral with said wafer and axially aligned with said waferpassage, said tubular contact retention tower extending rearwardly fromthe rearward face of said wafer to a rear free end, said tubular contactretention tower having a central passage therein that includes aforwardly facing shoulder, said tubular contact retention tower beingresiliently and radially expandable to permit said enlarged contactsection to pass therethrough upon forward insertion of the contactmember into the passage and boRe, said tubular contact retention towercontracting behind the rearwardly facing shoulder on the contact memberso that the forwardly facing shoulder within the tubular contactretention tower engages the rearwardly facing shoulder on the contactmember to limit rearward movement thereof in the passage and bore, saidtubular contact retention tower being substantially rigid in the axialdirection when in its contracted position so as to provide a positivestop against rearward movement of the respective contact member.